Synthesis of 1, 4-diazabicyclo (2.2.2) octane



ethanolamine charge.

2,977,363 SYNTHESIS OF 1,4-DIAZABICYCLO (2.2.2) O Adalbert Farkas and Jack H. Krause, Media, Pa.,

signors to l-loudr Process Co oration WiImin on If .1 u

y rp W rials each of which in itself 'would be economically un- Del., a corporation of Delaware No Drawing. Filed July 30, 1958, Ser. No. 751,854

I Claims. or. 260-268) 1 application is concerned'with the preparationof I l,4-d1azabicyc1o-(2.2.2)-octane, referred to hereinafter as triethylene diamine, in high recoverable yields from reaction efiluent mixtures as a product of high purity.

nited States Patentt) "T TZ-i these two materials, namely diethanolamine and ethylene diamine, are used as a mixed charge in an acid catalyzed reaction. 5

. These yields are inexcessuofany givenadditiveefiect. The reason therefore is not understood, but is of'significant value in that relatively high'yieldsigof triethylene diamine'cannow be obtained from low cost raw matesuited for "the production of triethylene diamine. In accordance with this invention, commercially "attractive yields of triethylene diamine areobtained by acid'cataly zed conversion, at temperatures in the range of 575- 900? F., ofra charge mixture of 50-75 mol percent diethanolamine an d 50-25 mol percent ethylene diamine.

Piperazine and other valuableby-products produced are readily separated. and-can be recovered therefrom- -w'Ihe preferred catalyst is silica-alumina, particularly of the type familiarly used in catalytic cracking of hydrocarbons, in. the form ofgranules, molded pellets, or

beads. 'Such catalysts include the synthetic dried geltype catalyst formed by suitable impregnation of silica While, the preparation of cyclic diamines of thistype had been attempted by organic chemists using many'difi erent methods, no suitable system for large-scale production of this compound, triethylene diamine, was available;

.Only low yields by-expensive and'involved, procedures,

Detective resultsfon the desiredreaction.

tion of triethylene diamine have suggested the use of alkyl, alkylol, or other substitutedamines as starting materials. Other work reported in Berichte has shown the preparation from diethanolamine hydrochloride by heat- 7 circumstances approximately 2% triethylene diamine was obtained. Other syntheses included the use of starting materials such as triethanolamine in the presence of ammonium chloride or reaction of ethanolamine hydrochloride with diethanolamine. Other work has shown the use of N-hydroxyethyl derivatives of piperazine using silica-alumina catalysts. In all of these procedures, with the exception of the method set forth in the above-identified co-pending application, the yields have been small. I Of the various reported methods, the ones showing the greatest. degree of promise have generally been those in which the cyclic amines are prepared in the presence of an acidic catalyst at elevated temperatures. In our investigation along the lines of improved methods for the preparation of triethylene diamine, a wide variety of.

charge stocks was tested. It was found'that only moderat e yields of triethylene diamine were obtained from amounts of triethylene diamine were obtained from dij It has now been discovered that surprising-and unexe pected results of a synergistic natureare obtained when are obtained substantially: in th ejs'ame o jde as with considerably more expen ive.- dis hy g charge, as'fwill be seen by ref gel, or by co-precipitation of the silicon and aluminum components, to provide a gelcomprising -90% by weight Slo to 40-10% by weight A1 0 and whichmay include therein other refractory metal oxides such. as

magnesia orzirconia. Other known silica-alumina catalysts. that maybe employed. include acid-activated clays alumina carrier, may also be used. V

'The desired triethylene diamine product is formedover a:reaction temperature range of from about 575 to 900 -F.;ftemperaturesin therange of from about 600to 750 .F.' are; preferred: Within this preferred temperature 7 range, space rates (volume of charge measured asliquid per volume of catalyst per hour) of-the order of..about 0.5 to 2,0 are likewise preferred. Smaller. or, greater somewhat-less efspace ates can lie-employed but. with.

The use of elevated pressure is n MM operation." In general, pressures fromatmosphe'ric to pounds per square inch gauge may be used; In some I I instances, particularly when operating at super-atmospheriopressureflt may be desirable to reduce the partial pressure of the amines in the reaction zone, whichmaybe accomplished by the addition of gaseous diluent, such. as hydrogen or inert gas in quantities of up to ten' mols per mol of the mixed amines charged. Sub-atmospheric" pressure operation, either with undilutedcharge or with; 1: c diluted charge wherein the charge"partialpressure would y; be less than atmospheric, appears to have noparticular beneficial effect nor any particularly detrimental effectat pressures as low as half an atmosphere.

conditions obtains considerably. poorer yields of triethylene diamine and is considerably less selective; when; diethanolamine is; the charge stock under similarficir cumsta'nces, theproduction of both triethyleneJdiainine; and piperazine is of such low order as to be ofno' practical interest. *Howeven'when these two materialsiare; I admixed. in approx'imately equimolar amounts and ,then. 1 charged to' acidjcatalyzed' reactions 'ate leyated tempera tures', surprisingly improved yields-of triethyl ncet th follow 1 DEA= diethanolamine.

EDA=ethylene diamine.

From the above table it is clearly evident that the actual results from runs 3 and 4 using substantially equimolar quantities of diethanolamine and ethylene diamine as the charge are far superior to the calculated values based on the results of runs 1 and 2.

The examples above are indicative of the operation of the invention. It is to be understood modifications may be used such as, for example, recycle operation in which selected portions of the product efiiuent after removal of the desired triethylene diamine and piperazine are recycled to the reaction zone along with the fresh mixed charge.

A distinct advantage is shown for the diethanolamineethylene diamine mixture over either ethylene diamine or diethanolamine when used alone. One advantage in the use of the mixture appears from the value of the-prodnot when compared to the cost of raw rnateriah For relative quantities of triethylene diamine when produced from the mixture of diethanolamine and ethylene diamine as compared to the charge stock consisting of diethylene triamine, product value is about four times as great based on the charge. Since it appears that there is a distinct synergistic effect in the production of triethylene diamine using the mixed charge of diethanolamine and ethylene diamine, the product yield per unit cost is distinctly and advantageously higher.

Obviously many modifications and variations of the invention as hereinbefore set forth may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are'indicated in the appended claims.

TABLE Triethylene diamine synthesis Run. 1 2. 3 4

Charge DEA EDA= Calculated ual ctual DEA-EDA. DLA-EDA DEA-EDA 1.1 1.2 1.1 .n 1.1. e p-- -700 F 100 52----" 700F 700F 625F Pressure..." Atmos Atmos Atmos Atmos Atmos Yields Wt. Percent Chg: Triethylene Diamine 1. R 5, a 2. Q 10. 12. 8.

Piperarine 0, 6 4 q 2 n 2, R 4. 3.

What is claimed is:

1. The method of preparing 1,4-diazabicyclo-(2.2.2)- octane comprising, contacting a charge mixture of to mol percent diethanolamine and 50 to 25 mol percent of ethylene diamine with an acidic siliceous cracking cata- "lyst at a temperature in the range of 575 to 900 F.

2. The method of preparing l,4-diazabicyclo-(2.2.2')- octane comprising, contacting a charge mixture of 50 to 75 mol percent diethanolamine and 50 to 25 mol percent of ethylene diamine with an acidic siliceous cracking catalyst at a temperature in the range of 600 to 750 F., at a space rate in the range of 0.5 to 2.0, and at a pressure in the range of 0.5 atmosphere to 100 pounds per square inch gauge.

3. The method in accordance with claim 2 wherein said catalyst comprises 60 to by weight Si0 and 40 to 10% by weight A1 0 4. The method in accordance with claim 2 wherein said catalyst contains a minor quantity of nickel.

5. The method of preparing 1,4-diazabicyclo-(2.2.2)- octane comprising, contacting a charge comprising approximately equimolar amounts of diethanolamine and ethylene diamine with an acidic silica-alumina cracking catalyst at conditions of a temperature in the range of about 625 to 700 F., a space rate of about 1, and at atmospheric pressure.

References Cited in the file of this patent .Chemische Berichte, vol. 75, pages 1302-1310 1942 

1. THE METHOD OF PREPARING 1,4-DIAZABICYCLO-(2.2.2)OCTANE COMPRISING, CONTACTING A CHARGE MIXTURE OF 50 TO 75 MOL PERCENT DIETHANOLAMINE AND 50 TO 25 MOL PERCENT OF ETHYLENE DIAMINE WITH AN ACIDIC SILICEOUS CRACKING CATALYST AT A TEMPERATURE IN THE RANGE OF 575 TO 900*F. 